1. Field of the Invention
The present invention relates to air conditioners, and more particularly, to a method for controlling flow rates of outdoor air supplied to a room and room air discharged to an outside of the room for ventilation for an air conditioner having a ventilating function.
2. Background of the Related Art
The air conditioner is an appliance for cooling or heating a room by using a property of refrigerant in which the refrigerant discharges or absorbs heat to/from an environment when the refrigerant undergoes a phase change.
In general, the air conditioner is provided with an indoor unit and an outdoor unit, wherein the air conditioner having the indoor unit and the outdoor unit combined into one unit is called as a unit type air conditioner, and the air conditioner having the indoor unit and the outdoor unit fabricated individually is called as a separate type air conditioner.
As a typical example of the unit type air conditioner, there is a window type air conditioner, and as the separate type air conditioners, there are a ceiling type air conditioner, a wall mounting type air conditioner, and a package type air conditioner. In a case of the ceiling type air conditioner, the indoor unit is installed in the ceiling, in a case of the wall mounting type, the indoor unit is mounted on a wall, and in a case of the package type air conditioner, the indoor unit stands on a floor in the room.
In general, the air conditioner is provided with a compressor, a condenser, an expansion device, and an evaporator. The compressor compresses low temperature/low pressure gas refrigerant to high temperature/high pressure refrigerant, and makes the refrigerant to pass through different units. The condenser condenses the gas refrigerant from the compressor into a liquid refrigerant. In this instance, as the refrigerant discharges heat when the refrigerant is condensed, the condenser discharges heat to an environment. As the heat is discharged from the condenser to the room, the room can be heated.
In general, as the expansion device, expanding the condensed refrigerant by decompression, capillary tubes are used. The evaporator vaporizes the expanded refrigerant, when the refrigerant absorbs heat to cool down air around the evaporator. When such a cooled down air is discharged to the room, the room can be cooled down.
In the meantime, for reducing heat loss during use of the air conditioner, the room is closed. Air in such a closed room is polluted gradually as time passes by. For an example, breathing of persons in the room makes a carbon dioxide content in the room air higher, and there is much dust circulating in the dry air. Therefore, after using the air conditioner for a time period, it is required to supply outdoor air fresh relative to the room air into the room. What is used for this is the very ventilating device.
Most of known related art ventilating devices employ a method in which one fan is used for force discharge of room air to an outside of the room. In this case, it is required to leave the window or door open for introduction of outdoor air into the room. In a case the ventilating system, while the room air is discharged forcibly, the room air is replaced with the outdoor air, naturally. In a ventilating process, there is even a problem in that the outdoor air introduced into the room is discharged to the outside of the room directly through a discharge duct before the outdoor air replaces the room air, adequately. Consequently, for complete ventilation of the room, a long time period is required.